1. Field of Invention
The present invention relates to a discontinuous multi-overlapped vehicle body member, and more particularly, to a discontinuous multi-overlapped vehicle body member having a discontinuous shape in which two or more members are inserted into each other in a longitudinal direction and multiply overlapped with each other.
2. Description of Related Art
In general, a vehicle body member is a structure constituting a vehicle body frame such as a side member, and supports a vehicle body to maintain stiffness. Further, the vehicle body member receives impact energy when collision of a vehicle occurs, and is deformed to absorb the impact energy.
FIGS. 1A and 1B illustrate a side member which is an example of a vehicle member according to the related art. Two plates 101 and 102 are manufactured using a steel plate by a press, and the two plates 101 and 102 are connected to each other through welding by connection flanges to manufacture a side member 100 in the form of a member.
The two plates 101 and 102 are respectively formed by the press so as to have a cross section of an “L” shape and a cross section of a reverse “L” shape. Connection flanges 101a and 102a are formed to integrally extend along edges of the cross sections. Thereafter, the connection flanges 101a and 102a are connected to each other such that the cross section of an “L” shape and the cross section of a reverse “L” shape are combined to be a cross section of a “” shape. Subsequently, the side member 100 is manufactured by forming welding portions 103 by welding a plurality of portions through, for example, spot welding.
The manufactured side members 100 are typically disposed at both sides of the vehicle body in a width direction when the side members constitute the vehicle body, and are also disposed to extend in a longitudinal direction of the vehicle body.
When impact is exerted to the vehicle body disposed in such a manner as represented by arrow of FIG. 2, that is, when the vehicle collides with another vehicle or object in a direction deflected from a longitudinal direction of the side member 100 (hereinafter, referred to as a deflection collision) other than a head-on collision where the vehicle accurately collides with the another vehicle or object in the longitudinal direction thereof, the impact exerted to the side member 100 is not accurately exerted in the longitudinal direction of the side member 100, and external impact is exerted in a direction deflected from the longitudinal direction.
For this reason, since the deflected external impact is exerted, the side member 100 is not accurately contracted and deformed in the longitudinal direction, and the deflected external impact acts on the side member 100 as a moment. Thus, buckling where the side member 100 is bent may occur at fragile portions of the side member 100.
When the buckling of the side member 100 is caused, an impact absorbing function of the side member 100 is degraded. Further, when the side member 100 does not properly absorb the impact, since impact is excessively transferred to other portions of the vehicle, the vehicle body may be excessively damaged, and safety of an occupant may be endangered.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.